We apply the P-wave refraction-tomography method to seismic data collected with a landstreamer. Refractiontomography inversion solutions were determined using regularization parameters that provided the most realistic near-surface solutions that best matched the dipping layer structure of nearby outcrops. A reasonably well matched solution was obtained using an unusual set of optimal regulariza...

Analysis of the refracted arrivals on a seismic reflection profile recorded along the wall of a tunnel at an iron mine near Thabazimbi, South Africa, shows variations in P-wave velocity in dolomite away from the de-stressed zone that vary between 4.4 and 7.2 kmrs, though values greater than 5.8 kmrs predominate along most of the profile. The seismic velocities at the tunnel wall, however, vary ...

geophysical techniques remain the only ways to remotely and non-destructively sense the earth’s near subsurface and as such have the most promising prospect for rapid and accurate detection of underground tunnels. today, electrical resistivity and seismic refraction geophysical methods have been greatly developed to identify structures and underground cavities. in this study, the ability of the...

The correct positioning of deep wells to monitor groundwater and entrained contaminants is greatly aided by using remote sensing methods. The geologic setting at the Anniston Army Depot (ANAD) consists of a sequence of fractured dolostones and clastic rocks that have been thrust-faulted, creating a highly complex and heterogeneous aquifer. The drilling of deep bedrock groundwater monitoring wel...

A cooperative program of seismic refraction profiling was completed in the vicinity of the Puerto Rico Trench by Hudson Laboratories, Woods Hole, Lamont, and Texas A. & M. Profiles completed near the western end of the Trench were analyzed at Hudson Laboratories. Five seismic layers are indicated below the water layer. The thickness/velocity relationships are as follows: 5.1 km of 1.5 km/sec. (...

In some cases, the variations in the subsurface rock property with time can be observed during fluid flow process because of changes in stress, pore pressure, temperature, degree of consolidation, and fluid content. Detecting these changes via their influence on the in situ elastic properties serves as the basis for timelapse monitoring. Acquisition and processing of high-fidelity time-lapse se...